Ill or injured persons may benefit from emergency oxygen in situations that include serious bleeding, divers with a decompression injury, difficulty breathing, suspected internal injury, and:a. Warning signs of serious illness. b. Partial thickness burns. c. Hyperventilation.

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.

"it built up in the atmosphere"

i think thats it, idk, i tried looking for this exact q& a for grad. and idk if i got this question right or sorry if im wrong